Wire form type insert retainer for a wafer style butterfly valve

ABSTRACT

A wafer style butterfly valve has a valve body including a through opening with a cylindrical wall coaxially surrounding an end portion of the fluid passage. The insert is retained within the valve body by at least one wire form held in an annular channel defined by facing annular grooves in the valve body wall and the insert peripheral wall. The wire form includes a member projecting therefrom for engaging a surface of the annular groove in the valve body wall or the annular groove in the insert peripheral wall. A tapered wall at one end of the insert provides for expansion of the wire form during insertion of the insert into the valve body.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is a continuation-in-part of U.S. application Ser.No. 621,066 filed June 15, 1984, now U.S. Pat. No. 4,575,048, issuedMar. 11, 1986 and relates to a wafer style butterfly valve, moreparticularly a wire form type arrangement for retaining the insertwithin the valve body by utilizing a wire form having a projectionextending therefrom.

2. Brief Description of the Prior Art

Butterfly valves are well known in the art. Also known are insert typebutterfly valves. Examples of such an Insert type butterfly valves areJamesbury Series 815W and 830W Wafer Sphere valves. It is common toposition a valve insert, such as a valve seat for a butterfly valve, ina recess at the axial end of the through opening in the valve body whichdefines the fluid flow passage. As a result, this insert can be reachedby detaching the adjacent conduit at the connecting flange.

When the adjacent conduit is connected to the valve body at theiradjoining flanges, the insert is held within the valve body and pressedbetween the valve body and the adjacent conduit, and so is securely heldin place. However, some means are necessary for retaining the insert inplace within the valve body before the attachment of the adjacentconduit. It has been known to drill matching bolt holes through theinsert and into a shoulder of the valve body, and then to bolt theinsert to the valve body via these matching holes. However, thistechnique has the shortcomings that the drilling of matching holes istime consuming and the resulting bolt heads extending from the insertmay mar the surface of a gasket at the axial end of the insert.Moreover, the insertion and removal of the insert from the valve bodyrequires bolting and unbolting, which is also time consuming.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an arrangement forretaining the insert of a wafer style butterfly valve which does notrequire bolting of the insert to the valve body.

It is a further object of the present invention to provide a wire formtype arrangement for retaining the insert of a wafer style butterflyvalve which is quickly and easily assembled and disassembled.

It is a further object of the present invention to provide anarrangement for retaining the insert in a wafer style butterfly valvewhich is simple to use and is formed of a minimum number of parts.

According to the present invention, the insert is retained within thevalve body by one or more resilient wire forms which are held in annularchannels defined by facing annular grooves of the insert and a wall ofthe valve body. The wire forms are circular in section and the annulargroove of the insert is shaped such that the wire forms are held in aresiliently stressed state within the annular recess of the insert. Theportions of the wire forms which extend into the recess of the wall ofthe valve body engages with this recess in the valve body and preventsthe insert from falling out of the valve body. At a predeterminedposition on each wire form a projection extends to engage with thesurface of annular groove in the wall of the valve body so as to securethe wire form in place.

According to a further feature of the invention, the peripheral surfaceof the insert has tapered axial end. This tapered end is inserted firstinto the valve body when introducing the insert thereinto. The taperedsurface contacts midportions of the straight sections of the wire formsand resiliently expands the wire forms. When more than about half of thesection of each wire form extends over the groove of the insert, thewire form will snap into this groove.

BRIEF DESCRIPTION OF THE DRAWINGS

Various other objects, features and attendant advantages of the presentinvention will be more fully appreciated as the same becomes betterunderstood from the following detailed description when considered inconnection with the accompanying drawings in which like referencecharacters designate like or corresponding parts throughout the severalviews and wherein:

FIG. 1 is a front view of a valve body, including the wire forms butexcluding the insert, as seen along the fluid flow direction;

FIG. 2 is a side view, partially in section, of the insert;

FIG. 3 is an enlarged sectional view of a portion of the insert andvalve body, showing the wire form positioned within the annular channeldefined by the cooperating annular grooves of the insert and valve body;and

FIG. 4 is an enlarged sectional view taken along line IV--IV of FIG. 3and which also demonstrates the manner in which the wire form is securedin place.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiment will now be described with reference to theattached figures, in which the same reference numeral is used todesignate the same element throughout the several views.

FIG. 1 illustrates a wafer style butterfly valve body as seen along thefluid flow directional axis. The body 2 is preferably circular but couldinstead be some other annular form. The butterfly valve 4 is shownschematically in an open state. The valve body, the valve and themechanism for opening and closing the valve are conventional exceptinsofar as specifically described herein.

The valve 4 is mounted within a through opening 6 within the valve bodywhich defines a fluid flow passage. At one end of the through openingare annular shoulders 8 and 10 which are separated by a cylindrical step12. Surrounding the radially outermost shoulder 10 is a cylindrical wall14 which terminates at the axial end surface 16 of the valve body.

The insert 20 is formed from a toroidal member having a generallyrectangular section. The radially outer periphery of the insert isshaped and sized so as to closely fit into the recess of the valve bodydefined by the shoulder 10 and the wall 14 of the through opening in thevalve body. In the case of the preferred embodiment, both the wall 14 ofthe valve body and the outer peripheral wall 22 of the insert areU-shaped. However, they could instead be hexagonal or of some othershape. A valve seat 24, which is preferably formed of an elastomericmaterial but may also be metal or a composite of the two, is fitted inan annular recess 26 of the insert 20 and is clamped between this recessand the shoulders 8 and 10 when the insert is fully introduced into thevalve body, as seen in FIG. 4.

As best seen in FIGS. 2 and 4, the end of the peripheral surface 22closest to the axial end surface 28 of the insert 20 includes an annulartaper 30. The purpose of the taper will be described below.

An annular groove 32 is formed in a mid-portion of the peripheralsurface 22 of the insert. The annular groove 32 has straight edges withrounded corners--not as deep as groove 34 as shown in FIG. 4. Theannular groove 34 is formed in the wall 14 of the valve body and ispositioned such that it faces the annular groove 32, and forms anannular channel with groove 32, when the insert 20 is fully introducedinto the valve body with the surfaces 10 and 28 in abutment, as seen inFIG. 4.

One or more resilient wire forms 36 are positionable in the annularchannel. The wire forms may encompass a significant portion of thecircumference so as to prevent the insert from falling out. Theresilient wire forms are preferably formed from generally circularsection wire stock made of a resilient material, such as spring steel.The wire forms 36 are preferably preformed into a shape approximating acurve by providing the otherwise straight sections 36a with sharp bends36b. A wire form which has been so preformed but which has not yet beenstressed by insertion into the annular channel is shown as 36 on theright side of FIG. 1. Preferably, one wire form 36 is employed and is ofsuch an arcuate length as to occupy slightly less than 50% of theannular groove 32. If more than one wire form is employed, the wireforms shall be of such a length and number that they together fill apredetermined portion of the arcuate length of the annular channel.

The insert of the present invention is introduced into, and retainedwithin, the valve body in the following manner. One or more wire forms36 of an arcuate configuration shown on the right side of FIG. 1 areintroduced into the annular groove 34 of the valve body. An insert 20having a seat 24 mounted thereon is then introduced into the throughhole 6 of the valve body with the annular taper 30 being introducedfirst. As the insert is being introduced into the through opening 6,mid-portions of the straight sections 36a of the wire forms will engagethe tapered surface 30 of the insert. Further introduction of the insertinto the through opening 6 will cause the wire forms to resilientlyexpand in a radially outward direction into the groove 34 by a cammingeffect of the tapered surface 30 until they are substantially fullyinserted into the groove 34 and rest on the cylindrical portion of theperipheral surface 22. The position of the wire form 36 within thegroove 34 at this time is shown in FIG. 4. Of course, each wire form isprevented from moving in the axial direction at this time by the axialwalls of the groove 34 and groove 32.

Once the wire form has been expanded as the insert is further introducedinto the through opening 6, the groove 32 will approach the position ofthe wire form 36. When more than half the section of a wire form 36 isover the groove 32, the resilience of the wire form 36 will create acamming action and the wire form 36 will tend to resilientlycontact-snap into the groove 32. Accordingly, a self-locking action isprovided for the insert 20 by the camming effect due to the engagementbetween the sections of the groove 32 and the wire form 36. Wire form36' shown at the left in FIG. 1 illustrates the final shape of the wireform after having been stressed by introduction into the groove 32 ofthe insert 20.

The above structure provides several advantages over the prior art.First, the expansion of the wire forms 36 during the introduction of theinsert 20 into the through opening 6 is provided by a tapered surface 30of the insert itself. Accordingly, a separate mandrel for expanding thewire form 36 is unnecessary. Moreover, the wire form and cooperatingannular groove 32 provide a self-locking camming effect for the insert20, as is described above, so that insertion of the insert issimplified. The assembly and construction of the valve is simplifiedsince a minimal number of parts is required and wire form 36 providesthe function of a locking element. The shape of the wire form 36, inwhich there are alternating straight sections 36a and bends 36b, assuresthat there is minimal surface area contact between the wire form and thetapered surface 30, thereby minimizing the frictional resistance of thewire form to sliding on the tapered surface 30 during insertintroduction. Finally, the bends 36b do not contact the radially inneredge of the groove 32 in the insert 20, and so extend further into thegroove 34, thereby further assuring the locking of the insert within thevalve body. Also the wire can be made of any corrosion resistantmaterial if necessary.

Each wire form 36 includes a projection 38, represented in dotted linesin FIG. 4 to demonstrate the manner in which it functions, extendingfrom at least one portion thereof for engaging the surface of annulargroove 34 so as to secure the wire form 36 in place. It is to beunderstood that such projection 38 could be located at any positionalong the length of wire form 36 and could project from wire form 36 inany direction so as to engage a corresponding surface portion of annulargroove 34 or, if desired, a surface portion of groove 32.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:
 1. A wafer style butterfly valve comprising:avalve body having a through opening forming a fluid flow passage andhaving a wall coaxially surrounding an end portion of said fluid flowpassage; a first annular groove in a surface of said wall; an inserthaving a peripheral surface shaped and sized such that said peripheralsurface closely faces said wall surface when said insert is positionedwithin said through opening, said insert including a second annulargroove being positioned in facing opposition to said first groove whensaid insert is positioned within said through opening, wherein saidfirst and second grooves define an annular channel; at least one wireform having an arcuate section defined by a plurality of interconnectedstraight sections in an undeformed state wherein said wire form includesfirst and second portions disposed in said first and second grooves,respectively, when said insert is positioned within said through openingso as to retain said insert within said through opening, furthercomprising engaging means for securing said wire form in place, saidengaging means comprising a member projecting outwardly from the surfaceof said wire form and engaging a surface of one of said first and secondannular grooves.
 2. The wafer style butterfly valve of claim 1 whereinsaid peripheral surface is tapered in a direction parallel to an axis ofsaid second groove, such that said tapered peripheral surface stressesand expands said at least one wire form as said insert is introducedinto said through opening.
 3. The wafer style butterfly valve of claim 2including a valve seat mounted on said insert.
 4. The wafer stylebutterfly valve of claim 2 wherein said wire form is formed of a singlepiece of resilient round stock.
 5. The wafer style butterfly valve ofclaim 2 wherein said wall and insert peripheral surface are cylindrical.6. The wafer style butterfly valve of claim 2 wherein said valve bodyincludes an annular shoulder adjacent said wall, said shoulder beingpositioned such that said insert abuts said shoulder when positioned inan inserted position in said through opening with said first and secondannular grooves in facing opposition.
 7. The wafer style butterfly valveof claim 2 wherein said second annular groove is located on a portion ofsaid peripheral surface not including said tapered portion.
 8. The waferstyle butterfly valve of claim 2 wherein said tapered peripheral surfaceengages midportions of said straight sections of said wire form andresiliently stresses said wire form when said insert is introduced intosaid recess.
 9. The wafer style butterfly valve of claim 1 including avalve seat mounted on said insert.
 10. The wafer style butterfly valveof claim 1 wherein said wire form is formed of a single piece ofresilient round stock.
 11. The wafer style butterfly valve of claim 5wherein said wire form is preformed in an unstressed state with straightsections jointed at sharply angled bent portions so as to form a curvedwire form.
 12. The wafer style butterfly valve of claim 1 wherein saidwall and insert peripheral surface are cylindrical.
 13. The wafer stylebutterfly valve of claim 1 wherein said valve body includes an annularshoulder adjacent said wall, said shoulder being positioned such thatsaid insert abuts said shoulder when positioned in an inserted positionin said through opening with said first and second annular grooves infacing opposition.
 14. The wafer style butterfly valve of claim 13wherein said insert includes a tapered peripheral surface and an axialend surface intersecting said tapered peripheral surface, said axial endsurface abutting said shoulder when said insert is in said insertedposition.
 15. The wafer style butterfly valve of claim 1 wherein saidmember projecting from said wire form further comprises a memberprojecting from at least one end portion of said wire form.